JP2019208087A - User device, base station, and signal transmission method - Google Patents

Abstract

To allocate radio resources at appropriate timing in a radio communication system in which radio frame configurations with different TTI lengths are mixed.SOLUTION: A user device in a radio communication system that supports TTI with a plurality of lengths and includes a base station and the user device includes: an acquisition unit that acquires, from the base station, information indicating a plurality of UL resources that are allocated to a plurality of symbols included in a TTI with a predetermined length and can transmit a scheduling request; and a transmission unit that selects a UL resource from the plurality of UL resources and transmits the scheduling request with the selected UL resource to the base station.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a user apparatus, a base station, and a signal transmission method.

  In LTE (Long Term Evolution), a wireless communication system called 5G has been studied to realize further increase in system capacity, further increase in data transmission speed, and further reduction in delay in a wireless section. Progressing. In 5G, various wireless technologies are being studied in order to satisfy the requirement to achieve a delay of 1 ms or less while achieving a throughput of 10 Gbps or more. In 5G, ultra-reliable and low latency communications (URLLC) that realizes ultra-low latency (for example, 0.5 ms) and highly reliable (for example, 99.999% reception probability) communication, eMBB (enhanced Mobile Broad Band) Various use cases have been proposed, and radio frame configurations and radio resource allocation methods suitable for these use cases are being studied. For example, in URLLC, in order to realize ultra-low delay, studies have been made to use a radio frame configuration having a TTI length shorter than eMBB.

NTT DoCoMo, Inc., NTT DOCOMO Technical Journal "5G Wireless Access Technology", January 2016

  In 5G, in order to efficiently use radio resources while supporting both eMBB and URLLC use cases, a radio resource used for eMBB communication and a radio resource used for URLLC communication are categorized in the same carrier. Static or dynamic sharing methods are being studied.

  Here, when traffic having different requirements is mixed in the same carrier, traffic that is not required to have a low delay (eMBB traffic) is allocated, and traffic that is required to have a low delay (URLLC). The quality of traffic) should be avoided. As described above, in URLLC, in order to realize ultra-low delay, it is considered to use a radio frame configuration having a TTI length shorter than eMBB. Therefore, when radio frame configurations having different TTI lengths are mixed, There is a need to provide a mechanism that allows radio resources to be allocated at an appropriate timing for each traffic.

  The disclosed technique has been made in view of the above, and provides a technique capable of allocating radio resources at an appropriate timing in a radio communication system in which radio frame configurations having different TTI lengths are mixed. Objective.

  A user apparatus of the disclosed technology is a user apparatus in a wireless communication system that supports a plurality of lengths of TTI and includes a base station and a user apparatus, and is assigned to a plurality of symbols included in the TTI of a predetermined length An acquisition unit that acquires information indicating a plurality of UL resources that can transmit a scheduling request from the base station, and selects a UL resource from the plurality of UL resources, and sends a scheduling request to the base station using the selected UL resource. A transmitting unit for transmitting.

  According to the disclosed technique, a technique capable of allocating radio resources at an appropriate timing in a radio communication system in which radio frame configurations having different TTI lengths are mixed is provided.

It is a figure which shows the structural example of the radio | wireless communications system which concerns on embodiment. It is a figure which shows the example of a setting of SR resource (UL slot). It is a figure which shows the example of a setting of SR resource (DL / UL shared slot). It is a figure for demonstrating the operation | movement which notifies the classification of UL resource which requests | requires allocation implicitly. It is a figure for demonstrating the operation | movement by which SR is transmitted during UL data transmission. It is a figure which shows UL resource divided into the several area | region which can transmit TB. It is a figure which shows an example of UL resource allocation by scheduling control information. It is a figure for demonstrating operation | movement when the allocated UL resource overlaps. It is a figure which shows an example of a function structure of the user apparatus which concerns on embodiment. It is a figure which shows an example of a function structure of the base station which concerns on embodiment. It is a figure which shows an example of the hardware constitutions of the base station and user apparatus which concern on embodiment.

  Embodiments of the present invention will be described below with reference to the drawings. The embodiment described below is only an example, and the embodiment to which the present invention is applied is not limited to the following embodiment. For example, although the wireless communication system according to the present embodiment assumes a system of a system compliant with LTE and 5G, the present invention is not limited to LTE and 5G, and can be applied to other systems. is there. In the present specification and claims, “LTE” corresponds to not only a communication method corresponding to Release 8 or 9 of 3GPP but also Release 10, 11, 12, 13, or Release 14 or later of 3GPP. It is used in a broad sense including the fifth generation communication system. “Resource” means a radio resource.

  In the following description, traffic / packet / data that is not required to have low delay is referred to as “eMBB traffic / packet / data”, and traffic / packet / data that is required to have low delay is referred to as “URLLC. Referred to as “traffic / packet / data”.

<System configuration>
FIG. 1 is a diagram illustrating a configuration example of a wireless communication system according to an embodiment. As shown in FIG. 1, the radio | wireless communications system which concerns on this Embodiment has the base station 10 and the user apparatus UE. In the example of FIG. 1, one base station 10 and one user apparatus UE are illustrated, but a plurality of base stations 10 may be included, or a plurality of user apparatuses UE may be included.

  The base station 10 has a function of performing scheduling with a predetermined TTI length and a function of performing scheduling with a TTI length shorter than the predetermined TTI length in a radio frame within a carrier (in a cell). The predetermined TTI length is used when allocating resources for eMBB traffic (may be referred to as scheduling), and a TTI length shorter than the predetermined TTI length is used when allocating resources for URLLC traffic. It is assumed that it will be used.

  The user apparatus UE has a function of performing communication using a resource allocated with a predetermined TTI length and a function of performing communication with a resource allocated with a TTI length shorter than the predetermined TTI length. Note that the user apparatus UE is either of a function of performing communication using a resource allocated with a predetermined TTI length and a function of performing communication with a resource allocated with a TTI length shorter than the predetermined TTI length. However, the user apparatus UE according to the present embodiment has a function of performing communication using at least a resource allocated with a predetermined TTI length unless otherwise specified. Assuming that Further, when a UL packet to be transmitted is generated, the user apparatus UE transmits an SR (Scheduling Request) to the base station 10 to request the base station 10 to allocate UL resources.

  In the following description, a predetermined TTI length is referred to as “normal TTI” for convenience, and a TTI length shorter than the predetermined TTI length is referred to as “short TTI” for convenience. In the present embodiment, description will be made on the assumption that one normal TTI is the same as the time length of one slot, but one normal TTI is a time of a plurality of slots (for example, two slots as in the conventional LTE). It may be the same as the length. One normal TTI may be the same as the time length of one subframe. The number of symbols constituting one normal TTI may be the same as the number of symbols in conventional LTE (for example, 12 symbols or 14 symbols), but is not limited to this, and is different from the conventional LTE. It may be a number (for example, 7 symbols).

  The short TTI corresponds to an arbitrary partial symbol among a plurality of symbols constituting the normal TTI. Specifically, assuming that the normal TTI is composed of 14 symbols, the base station 10 performs an operation of scheduling, for example, the 4th and 5th symbols of these 14 symbols as short TTIs. . The time length of the short TTI may be referred to as a mini-slot.

<Processing procedure>
Then, the process procedure which the radio | wireless communications system which concerns on this Embodiment performs is demonstrated. The base station 10 sets in advance a resource capable of transmitting SR from the user apparatus UE (hereinafter, a resource capable of transmitting SR is referred to as “SR resource” for convenience) in the user apparatus UE. When a UL packet to be transmitted occurs, the base station 10 is requested to allocate a UL resource by transmitting an SR using a preset SR resource.

(About SR resource settings)
FIG. 2 is a diagram illustrating an example of setting SR resources (UL slot). FIG. 3 is a diagram showing an example of setting SR resources (DL / UL shared slot). 2 and 3 assume the FDD scheme and the TDD scheme, respectively, but FIG. 2 includes slots in which all symbols are set to UL in the TDD scheme. As shown in FIG. 2A and FIG. 3A, the base station 10 sets one or a plurality of SR resources in the frequency direction for each of a plurality of different symbols in one TTI. Also, as shown in FIGS. 2B and 3B, when a band for transmitting the UL control signal is set in a predetermined band in the system band, the base station 10 In the band, one or a plurality of SR resources may be set in the frequency direction for each of a plurality of different symbols in one TTI. Thereby, when the UL packet which should be transmitted arises, since the user apparatus UE can transmit SR with the SR resource close to the timing at which the UL packet occurs, the UL resource can be quickly allocated. Can be requested. In addition, the position of the DL resource shown in FIG. 3 is an example, and is not intended to be limited to the illustrated position.

  The SR may be a predetermined signal sequence or data having a predetermined data length (hereinafter referred to as “data type SR”). In addition, the SR may be code-multiplexed in order to use the same SR resource among a plurality of user apparatuses UE. When the transmission of SR and the transmission of UL data are performed simultaneously, the reference signal used for demodulation of the data type SR and the reference signal used for demodulation of UL data may be common or independent. Good. In the latter case, the user apparatus UE may transmit both the data type SR and the reference signal using the SR resource. In the data type SR, only control information such as BSR (Buffer Status Report) may be transmitted, or short data of a certain length or less may be transmitted.

  The position of the SR resource is set (notified) from the base station 10 to the user apparatus UE using broadcast information (broadcast information), RRC (Radio Resource Control) signaling, layer 2 control information, or layer 1 control information. Note that the base station 10 notifies the user apparatus UE of a plurality of SR resource candidates using broadcast information (broadcast information) or RRC signaling, and for the SR resources that are actually set in the user apparatus UE, Notification may be made using control information or layer 1 control information. Accordingly, it is possible to dynamically set an appropriate SR resource in the user apparatus UE according to the presence / absence of the possibility of allocating a short TTI resource to the user apparatus UE and the scheduling situation.

[Notification of UL resource type for which allocation is requested]
By transmitting the SR according to the transmission method of SR associated with the UL resource type (UL resource of normal TTI or UL resource of short TTI) for which the user apparatus UE requests allocation, It may be possible to notify the base station 10 implicitly. The SR transmission method associated with the type of the UL resource includes, for example, a time resource for transmitting the SR, a frequency resource for transmitting the SR, a sequence of the transmitted SR, the number of symbols occupied by the transmitted SR, And / or the number of subcarriers occupied by the transmitted SR. The association between the SR transmission method and the UL resource type may be defined in the standard specification, may be pre-configured in the user apparatus UE, or may be RRC signaling or broadcast information ( (Broadcast information) may be set in the user apparatus UE. Further, the SR transmission method may be associated with the uplink logical channel and / or the packet priority.

  FIG. 4 shows a specific example in the case of notifying the type of UL resource for which the user apparatus UE requests allocation using the time resource for transmitting the SR. For example, in the example of FIGS. 4A and 4B, when the SR is received by the SR resource included in the first half area (the area indicated by “Short TTI scheduling request” in the figure), the base station 10 When the user apparatus UE recognizes that it is requesting a short TTI UL resource and receives an SR with an SR resource included in the latter half of the area (area indicated by “normal TTI scheduling request” in the figure), the base station 10 recognizes that the user apparatus UE is requesting the UL resource of the normal TTI.

  Note that the SR resource area corresponding to the short TTI scheduling request and the SR resource area corresponding to the normal TTI scheduling request may overlap. For example, in the example of FIG. 4A and FIG. 4B, when the SR is received by the SR resource included in the latter half of the area, the base station 10 determines that the user apparatus UE is either normal TTI or short TTI. It may be recognized that one UL resource is requested. In this case, the base station 10 determines which UL resource the user apparatus UE is requesting from the normal TTI or the short TTI, between the user apparatus UE and the base station 10. You may make it judge according to the classification etc. of the radio bearer established. For example, when the determination is made based on the capability of the user apparatus UE, the base station 10 allocates a short TTI UL resource when the user apparatus UE has the capability of supporting the short TTI, and has the capability of supporting the short TTI. If not, it is conceivable to allocate a normal TTI UL resource. Also, when determining by the type of radio bearer, the base station 10 allocates a short TTI UL resource when the URLLC radio bearer is established, and normal TTI UL when the eMBB radio bearer is established. It is conceivable to allocate resources.

(About SR transmission method)
One SR is defined in advance in the standard specification or higher layer (broadcast information or RRC signaling) so as to mean a predetermined data size. When the user apparatus UE requests allocation of UL resources, the user apparatus UE You may make it transmit the number of SR according to the data size (data size accumulate | stored in the transmission buffer of the user apparatus UE) of the UL packet which is due to be transmitted. As a specific example, when one SR is defined in advance to mean 200 bytes and 550 bytes of data are stored in the transmission buffer in the user apparatus UE, the user apparatus UE exists in one normal TTI. Three SRs may be transmitted using three SR resources. The base station 10 can recognize the size of data scheduled to be transmitted by the user apparatus UE according to the number of SRs received within one normal TTI, and can reflect the size in the scheduling process.

  Further, as described above, when the UL resource type for which allocation is requested is implicitly notified to the base station 10 based on the region (position) of the SR resource, the user apparatus UE sets the UL resource type for which allocation is requested. By transmitting a plurality of SRs in the corresponding area, it is possible to realize an operation of notifying the base station 10 of the data size in the transmission buffer corresponding to the UL resource type for which allocation is requested.

  As another example, the user apparatus UE transmits SR using a plurality of (or all) SR resources in one normal TTI, thereby improving the SR detection accuracy on the base station 10 side. Also good. A plurality (or all) of SR resources for transmitting the SR may be limited to the SR resources in the above-described region. Further, the user apparatus UE may transmit the SR using a predetermined ratio (for example, at least 50% or more) of SR resources in one normal TTI according to radio quality (DL reception quality or the like). . The base station 10 side reduces the power consumption of the user apparatus UE by reducing the number of SRs to be transmitted when the radio quality is good, and by transmitting many SRs when the radio quality is degraded. SR detection accuracy can be improved.

  Moreover, when transmitting several SR, the user apparatus UE may be made to change a transmission power parameter according to the area | region where SR resource is set. For example, when the SR resource is set in the resource area allocated to the UL data channel, the user apparatus UE may transmit the SR with the transmission power corresponding to the UL data channel. For example, when the SR resource is set in the resource area allocated to the UL control channel, the user apparatus UE may transmit the SR with the transmission power corresponding to the UL control channel. This makes it possible to suppress interference between the SR and signals transmitted on other channels.

(About SR transmission during UL data transmission)
By applying OFDM (Orthogonal Frequency Division Multiplexing) to the UL, the user apparatus UE may simultaneously transmit SR and UL data with the same symbol.

  The user apparatus UE having the capability of transmitting SR during UL data transmission may transmit SR in parallel even when the UL data is being transmitted using the normal TTI UL resource. For example, as illustrated in FIG. 5, when a URLLC packet is generated in an upper layer (such as an application layer) after starting transmission of UL data using the allocated UL resource, the user apparatus UE generates a URLLC packet. The SR may be transmitted using the SR resource at the next timing. Thereby, for example, even when the user apparatus UE is transmitting eMBB data, the user apparatus UE can request the base station 10 to allocate UL resources for URLLC data transmission. Transmission can be performed quickly.

  Note that, when the user apparatus UE transmits an SR after transmitting UL data with a normal TTI, the user apparatus UE is concerned only when it is determined that a delay condition (for example, less than 1 normal TTI) required for a URLLC packet cannot be satisfied. The SR may be transmitted in parallel with the transmission of the UL data on the assumption that there is no UL resource corresponding to the packet. When determining that the delay condition can be satisfied, the user apparatus UE may transmit the SR after the transmission of the UL data is completed (for example, in the next normal TTI).

  The user apparatus UE that does not have the capability of transmitting SR during UL data transmission, or the user apparatus UE instructed by the base station 10 not to transmit SR during UL data transmission uses the allocated UL resource. The SR may be transmitted after dropping (stopping) or puncturing (no transmission) the transmission of UL data.

(Operations related to UL data transmission)
In the conventional LTE, when data of a plurality of logical channels is accumulated in the transmission buffer in the user apparatus UE, it is defined that the data is mapped to the UL resource and transmitted in the order of higher priority data. However, in 5G, even if the data has high priority, there are data that requires further low delay and high reliability such as URLLC, and data that does not require high delay and reliability such as eMBB. It is assumed that it exists. For this reason, even if the data has a high priority, it is desirable that data that requires further low delay and high reliability, such as URLLC, be transmitted using UL resources that satisfy the requirements.

  Therefore, normal UL data (for example, high priority packets, data belonging to a specific logical channel or a specific logical connection, etc.) and low UL and high reliability are required for normal UL data. When it is determined that the request condition cannot be satisfied when transmission is performed using the UL resource allocated by the TTI, the user apparatus UE may not transmit specific UL data using the UL resource allocated by the normal TTI. As a result, it is possible to avoid that specific UL data that requires low delay and high reliability is transmitted using UL resources that do not satisfy the required conditions.

  Further, when there is no other UL data scheduled to be transmitted in addition to the specific UL data, the user apparatus UE may transmit padding data using the allocated UL resource. It is possible to prevent the base station 10 from erroneously recognizing that reception of UL data has failed and assigning UL resources again.

  Even when it is determined that the request condition cannot be satisfied, if the SR resource is not set, the user apparatus UE cannot request the base station 10 to allocate another UL resource. Therefore, even when it is determined that the user apparatus UE cannot satisfy the required condition, if the SR resource is not set within the period of the UL resource allocated by the normal TTI, the UL allocated by the normal TTI You may make it transmit UL data with a resource. On the other hand, when the SR resource is set within the period of the UL resource allocated in the normal TTI, the user apparatus UE transmits another SR using the set SR resource, thereby causing another UL resource (short). The base station 10 may be requested to allocate a TTI (UL resource).

  In addition, the base station 10 can transmit UL data to UL resource scheduling control information (UL grant) so that the user apparatus UE can easily recognize delay and reliability conditions in the allocated UL resource. An identifier indicating the type (URLLC data, eMBB data, etc.) or an identifier indicating resource quality (delay, reliability, etc.) may be included. The user apparatus UE can easily determine whether or not to transmit UL data based on the identifier. The identifier indicating the type of UL data may be a logical channel number or a priority identifier. The identifier indicating the type of UL data may be a CRC mask (RNTI) of scheduling control information including the identifier, or may be a reference signal position / sequence of scheduling control information including the identifier. Signaling overhead can be reduced. The type of UL data may be identified based on the resource (time, frequency, code) for which scheduling control information is notified. The type of UL data associated with the resource to which the scheduling control information is notified may be determined in advance, or the base station 10 may be set by higher layer signaling.

(Regarding resource allocation in TTI)
When the base station 10 allocates a normal TTI UL resource, the UL resource is divided into a plurality of areas in the time direction within 1 TTI, and each UL resource can transmit a TB (Transport Block). May be assigned. Further, the user apparatus UE may transmit the BSR to the base station 10 using a UL resource corresponding to any one of the UL resources divided into a plurality of areas.

  This will be specifically described with reference to the drawings. It is assumed that four regions each capable of transmitting a TB are allocated in the time direction within one normal TTI. For example, as illustrated in FIG. 6A, for example, when a URLLC packet is generated in the user apparatus UE at the time of the second area from the left, the user apparatus UE In the TB to be transmitted in (1), a BSR that explicitly or implicitly indicates that a short TTI UL resource allocation is requested is transmitted. In addition, since the BSR requests UL resource allocation in the same manner as SR, the user apparatus UE can also be expressed as transmitting BSR as “SR”. Thereby, it is not necessary to transmit the SR in order to request allocation of the short TTI UL resource, and it is possible to reduce the overhead of signaling transmitted and received between the user apparatus UE and the base station 10.

  Further, as illustrated in FIG. 6B, the user apparatus UE may transmit the URLLC packet included in the TB instead of the BSR. The user apparatus UE may determine whether it is possible to transmit a URLLC packet based on MCS (Modulation and Coding Scheme) applied to the assigned UL resource. Also, the base station 10 can transmit the UL resource scheduling control information (UL grant) in each area so that the user apparatus UE can easily determine whether or not the URLLC packet can be transmitted. An identifier indicating the type of UL data (URLLC data, eMBB data, etc.), or an identifier indicating the quality of resources (delay and reliability level, etc.) of each area may be included. The identifier indicating the type of UL data may be a logical channel number or a priority identifier. The identifier indicating the type of UL data may be a CRC mask (RNTI) of scheduling control information including the identifier, or may be a reference signal position / sequence of scheduling control information including the identifier. Signaling overhead can be reduced. The type of UL data may be identified based on the resource (time, frequency, code) for which scheduling control information is notified. The type of UL data associated with the resource to which the scheduling control information is notified may be determined in advance, or the base station 10 may be set by higher layer signaling.

[About HARQ process ID]
As described above, the base station 10 assigns the HARQ process ID for each TB to the scheduling control information (UL grant) shown in FIG. 7 when allocating UL resources divided into a plurality of areas each capable of transmitting a TB. It may be included. Also, the base station 10 does not include the HARQ process ID for each TB, but includes only the first HARQ process ID among the HARQ process IDs grouped in advance using an upper layer (RRC signaling or the like). May be. For example, when HARQ process IDs # 1, # 2, # 3, and # 4 are grouped, the base station 10 may include only the HARQ process ID # 1 in the scheduling control information (UL grant). . The user apparatus UE can grasp the HARQ process ID corresponding to each TB, and can perform retransmission control by HARQ for each TB.

  When retransmitting the TB, the user apparatus UE may transmit the retransmission TB using the normal TTI UL resource assigned at another timing, or transmit the retransmission TB using the short TTI UL resource. Also good. The latter case can be realized by setting each of a plurality of areas capable of transmitting a plurality of TBs and the short TTI to have the same length, and can shorten a retransmission delay. Become.

  As described above, the operation described in “(Resource Allocation within TTI)” can also be applied to DL (Downlink). In this case, the user apparatus UE may transmit ACK / NACK to the base station 10 for each TB using a resource instructed for each TB as a resource for transmitting ACK / NACK.

  Also, the user apparatus UE may transmit bitmap information indicating ACK / NACK for each HARQ process ID to the base station 10 using one resource for transmitting ACK / NACK. Further, the user apparatus UE may merge and transmit the ACK / NACK for each HARQ process ID to the base station 10 using one resource for transmitting ACK / NACK. For example, the user apparatus UE may transmit an ACK only when all of the ACKs / NACKs for each HARQ process ID are ACK, and may transmit a NACK when at least one NACK. Thereby, in DL, it becomes possible to transmit ACK / NACK for a plurality of TBs collectively with one resource, so that signaling overhead can be reduced.

[Operation when scheduling is duplicated]
The user apparatus UE receives both the scheduling control information (UL grant) related to the normal TTI and the scheduling control information (UL grant) related to the short TTI from the base station 10, and the resource allocated as the normal TTI When the resource allocated as the short TTI overlaps, the overlapping resource may be updated (overwritten) with the scheduling control information regarding the short TTI, or the scheduling control information regarding the short TTI may be discarded (ignored). You may do it. In the former case, the user apparatus UE transmits, for example, a TB including eMBB data using non-overlapping resources (A, B, and D in FIG. 8A), and overlapping resources (C in FIG. 8A). Thus, it is conceivable to perform an operation of transmitting a TB including URLLC data. In the latter case, for example, the user apparatus UE may perform an operation of transmitting a TB including eMBB data with each resource (A, B, C, and D in FIG. 8A).

  When the user apparatus UE updates (overwrites) a part of UL resources divided into a plurality of areas and transmits short TTI UL data, the BLER (Block Error Rate) of the normal TTI UL data is degraded. Since it does not occur, it is possible to improve the frequency utilization efficiency by simply puncturing a part of the normal TTI UL resource as compared with the case of transmitting short TTI data.

  Note that the user apparatus UE determines which of the scheduling control information related to the normal TTI and the scheduling control information related to the short TTI has priority, based on the time when the scheduling control information is received (for example, the one received later) May be given priority). In addition, the user apparatus UE may determine which is prioritized based on the type / flag or the like included in the scheduling control information (for example, the one with a shorter delay during data transmission is prioritized). .

  As another method, the user apparatus UE receives both the scheduling control information related to the normal TTI and the scheduling control information related to the short TTI from the base station 10, and the resource allocated as the normal TTI is short-circuited. If the resource allocated as TTI overlaps, nothing may be transmitted (data is dropped) with the overlapping resource (C in FIG. 8B).

<Functional configuration>
(User device)
FIG. 9 is a diagram illustrating an example of a functional configuration of the user apparatus according to the embodiment. As illustrated in FIG. 9, the user apparatus UE includes a signal transmission unit 101, a signal reception unit 102, and an acquisition unit 103. Note that FIG. 9 shows only functional units that are particularly related to the embodiment of the present invention in the user apparatus UE. Further, the functional configuration shown in FIG. 9 is merely an example. As long as the operation according to the present embodiment can be executed, the function classification and the name of the function unit may be anything.

  The signal transmission unit 101 has a function of generating various physical layer signals from a signal to be transmitted to the base station 10 and wirelessly transmitting the signals. The signal receiving unit 102 has a function of wirelessly receiving various signals from the base station 10 and acquiring higher layer signals from the received physical layer signals.

  The signal transmission unit 101 has a function of selecting an SR resource from a plurality of SR resources and transmitting the SR to the base station 10 using the selected SR resource. Further, when requesting scheduling of UL resources that can transmit data with a short TTI, the signal transmission unit 101 transmits SR according to an SR transmission method indicating that scheduling of UL resources that can transmit data with a short TTI is requested. You may make it do. Further, one SR means a data size of a predetermined unit, and the signal transmission unit 101 is based on the data size of the predetermined unit and the data size of UL data stored in the transmission buffer of the user apparatus UE. The number of SRs to be transmitted to the base station 10 may be calculated, the same number of SR resources as the calculated number may be selected, and the SR may be transmitted using each of the selected plurality of SR resources. Further, the signal transmission unit 101 may transmit the BSR by using the UL resource corresponding to any one of the UL resources divided into a plurality of regions.

  The acquisition unit 103 has a function of acquiring, from the base station 10, information indicating a plurality of SR resources that can be transmitted to the SR, allocated to a plurality of symbols included in the normal TTI. Further, the acquisition unit 103 is a UL resource that is divided into a plurality of regions in the time direction within the normal TTI, and the scheduling information indicating the UL resource that can transmit the transport block in each of the UL resources. You may make it acquire from.

(base station)
FIG. 10 is a diagram illustrating an example of a functional configuration of the base station according to the embodiment. As illustrated in FIG. 10, the base station 10 includes a signal transmission unit 201, a signal reception unit 202, a scheduling unit 203, and a notification unit 204. FIG. 10 shows only functional units that are particularly related to the embodiment of the present invention in the base station 10.

  The signal transmission unit 201 has a function of generating various physical layer signals from a higher layer signal to be transmitted from the base station 10 and wirelessly transmitting the signals. The signal receiving unit 202 has a function of wirelessly receiving various signals from the user apparatus UE and acquiring a higher layer signal from the received physical layer signal. In addition, the signal receiving unit 202 has a function of receiving SR using one or more SR resources selected from a plurality of SR resources.

  The scheduling unit 203 has a function of assigning UL resources to the user apparatus UE. The notification unit 204 has a function of notifying the user apparatus UE of information indicating a plurality of SR resources that are assigned to a plurality of symbols in the normal TTI and can transmit an SR.

<Hardware configuration>
The block diagrams (FIGS. 9 and 10) used in the description of the above embodiment show functional unit blocks. These functional blocks (components) are realized by any combination of hardware and / or software. Further, the means for realizing each functional block is not particularly limited. That is, each functional block may be realized by one device physically and / or logically coupled, and two or more devices physically and / or logically separated may be directly and / or indirectly. (For example, wired and / or wireless) and may be realized by these plural devices.

  For example, the base station 10 and the user apparatus UE in an embodiment of the present invention may function as a computer that performs processing of the signal transmission method of the present invention. FIG. 11 is a diagram illustrating an example of a hardware configuration of the base station 10 and the user apparatus UE according to the embodiment. The base station 10 and the user apparatus UE described above may be physically configured as a computer apparatus including a processor 1001, a memory 1002, a storage 1003, a communication apparatus 1004, an input apparatus 1005, an output apparatus 1006, a bus 1007, and the like. .

  In the following description, the term “apparatus” can be read as a circuit, a device, a unit, or the like. The hardware configurations of the base station 10 and the user apparatus UE may be configured to include one or a plurality of the apparatuses illustrated in the figure, or may be configured not to include some apparatuses.

  Each function in the base station 10 and the user apparatus UE is obtained by reading predetermined software (program) on hardware such as the processor 1001 and the memory 1002, so that the processor 1001 performs an operation and performs communication by the communication apparatus 1004 and memory 1002. This is realized by controlling reading and / or writing of data in the storage 1003.

  For example, the processor 1001 controls the entire computer by operating an operating system. The processor 1001 may be configured by a central processing unit (CPU) including an interface with peripheral devices, a control device, an arithmetic device, a register, and the like. For example, the signal transmission unit 101, the signal reception unit 102 and the acquisition unit 103 of the user apparatus UE, the signal transmission unit 201, the signal reception unit 202, the scheduling unit 203, and the notification unit 204 of the base station 10 may be realized by the processor 1001. Good.

  The processor 1001 reads a program (program code), a software module, or data from the storage 1003 and / or the communication device 1004 to the memory 1002, and executes various processes according to these. As the program, a program that causes a computer to execute at least a part of the operations described in the above embodiments is used. For example, the signal transmission unit 101, the signal reception unit 102, and the acquisition unit 103 of the user apparatus UE, the signal transmission unit 201, the signal reception unit 202, the scheduling unit 203, and the notification unit 204 of the base station 10 are stored in the memory 1002, and the processor It may be realized by a control program operating in 1001, and may be realized in the same manner for other functional blocks. Although the above-described various processes have been described as being executed by one processor 1001, they may be executed simultaneously or sequentially by two or more processors 1001. The processor 1001 may be implemented by one or more chips. Note that the program may be transmitted from a network via a telecommunication line.

  The memory 1002 is a computer-readable recording medium and includes, for example, at least one of ROM (Read Only Memory), EPROM (Erasable Programmable ROM), EEPROM (Electrically Erasable Programmable ROM), RAM (Random Access Memory), and the like. May be. The memory 1002 may be called a register, a cache, a main memory (main storage device), or the like. The memory 1002 can store a program (program code), a software module, and the like that can be executed to implement the signal transmission method according to the embodiment of the present invention.

  The storage 1003 is a computer-readable recording medium such as an optical disc such as a CD-ROM (Compact Disc ROM), a hard disc drive, a flexible disc, a magneto-optical disc (eg, a compact disc, a digital versatile disc, a Blu-ray). (Registered trademark) disk, smart card, flash memory (for example, card, stick, key drive), floppy (registered trademark) disk, magnetic strip, and the like. The storage 1003 may be referred to as an auxiliary storage device. The storage medium described above may be, for example, a database, server, or other suitable medium including the memory 1002 and / or the storage 1003.

  The communication device 1004 is hardware (transmission / reception device) for performing communication between computers via a wired and / or wireless network, and is also referred to as a network device, a network controller, a network card, a communication module, or the like. For example, the signal transmission unit 101, the signal reception unit 102, the signal transmission unit 201, and the signal reception unit 202 of the user apparatus UE may be realized by the communication device 1004.

  The input device 1005 is an input device (for example, a keyboard, a mouse, a microphone, a switch, a button, a sensor, or the like) that accepts an external input. The output device 1006 is an output device (for example, a display, a speaker, an LED lamp, etc.) that performs output to the outside. The input device 1005 and the output device 1006 may have an integrated configuration (for example, a touch panel).

  Each device such as the processor 1001 and the memory 1002 is connected by a bus 1007 for communicating information. The bus 1007 may be configured with a single bus or may be configured with different buses between apparatuses.

  In addition, the base station 10 and the user apparatus UE include hardware such as a microprocessor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a programmable logic device (PLD), and a field programmable gate array (FPGA). The hardware may be configured, and a part or all of each functional block may be realized by the hardware. For example, the processor 1001 may be implemented by at least one of these hardware.

<Summary>
As described above, according to the embodiment, a user apparatus in a radio communication system that supports a plurality of lengths of TTI and includes a base station and a user apparatus, and includes a plurality of symbols included in a TTI of a predetermined length. An acquisition unit for acquiring, from a base station, information indicating a plurality of assigned UL resources that can transmit a scheduling request; and selecting a UL resource from the plurality of UL resources, and sending the scheduling request using the selected UL resource. And a transmission unit for transmitting to a user device. According to this user apparatus UE, a technique capable of allocating radio resources at appropriate timing is provided in a radio communication system in which radio frame configurations having different TTI lengths are mixed.

  In addition, when the transmission unit requests allocation of a UL resource capable of transmitting data with a TTI having a time length shorter than the TTI having the predetermined length, data transmission is performed with a TTI having a time length shorter than the TTI having the predetermined length. The scheduling request may be transmitted according to a scheduling request transmission method that indicates requesting allocation of a possible UL resource. As a result, the user apparatus UE can explicitly request the base station 10 to allocate a short TTI UL resource.

  One scheduling request means a data size in a predetermined unit, and the transmission unit is based on the data size in the predetermined unit and the data size of UL data stored in the transmission buffer of the user apparatus. The number of scheduling requests to be transmitted to the base station is calculated, the same number of UL resources as the calculated number are selected from the plurality of UL resources, and the scheduling request is transmitted by each of the selected plurality of UL resources. You may do it. Thereby, the user apparatus UE can notify the base station 10 of the data size of data scheduled to be transmitted according to the number of SRs to be transmitted.

  Also, the acquisition unit is a UL resource that is divided into a plurality of regions in the time direction within the TTI of the predetermined length, and indicates a UL resource that can transmit a transport block with each of the UL resources. The information is acquired from the base station, and the transmission unit transmits a buffer status report as the scheduling request using a UL resource corresponding to any one of the UL resources divided into the plurality of regions. It may be. Thereby, the user apparatus UE can transmit a plurality of transport blocks within the normal TTI. Moreover, since the user apparatus UE can transmit a BSR in an arbitrary area within the normal TTI, it is possible to promptly request the base station 10 to allocate UL resources.

  In addition, according to the embodiment, the scheduling request is a base station in a wireless communication system that supports a plurality of TTI lengths and includes a base station and a user apparatus, and is allocated to a plurality of symbols in one TTI. A base station comprising: a notification unit for notifying the user apparatus of information indicating a plurality of UL resources capable of transmitting a message; and a reception unit for receiving a scheduling request using one or more UL resources selected from the plurality of UL resources. Is provided. According to this base station 10, a technique is provided that can allocate radio resources at appropriate timing in a radio communication system in which radio frame configurations having different TTI lengths are mixed.

  In addition, according to the embodiment, there is provided a signal transmission method executed by a user apparatus in a radio communication system that supports a plurality of lengths of TTI and includes a base station and a user apparatus, wherein the TTI has a predetermined length. Acquiring from a base station information indicating a plurality of UL resources that can be transmitted to a scheduling request, assigned to a plurality of included symbols, selecting a UL resource from the plurality of UL resources, and scheduling using the selected UL resource Transmitting a request to the base station. According to this signal transmission method, there is provided a technique capable of allocating radio resources at an appropriate timing in a radio communication system in which radio frame configurations having different TTI lengths are mixed.

<Supplement of embodiment>
The reference signal may be abbreviated as RS (Reference Signal), and may be referred to as a pilot depending on an applied standard.

  Each aspect / embodiment described herein includes LTE (Long Term Evolution), LTE-A (LTE-Advanced), SUPER 3G, IMT-Advanced, 4G, 5G, FRA (Future Radio Access), W-CDMA. (Registered trademark), GSM (registered trademark), CDMA2000, UMB (Ultra Mobile Broadband), IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, UWB (Ultra-WideBand), The present invention may be applied to a Bluetooth (registered trademark), a system using another appropriate system, and / or a next generation system extended based on the system.

  The processing procedures, sequences, flowcharts, and the like of each aspect / embodiment described in this specification may be switched in order as long as there is no contradiction. For example, the methods described herein present the elements of the various steps in an exemplary order and are not limited to the specific order presented.

  The specific operation assumed to be performed by the base station in this specification may be performed by its upper node in some cases. In a network consisting of one or more network nodes having a base station, various operations performed for communication with the terminal may be performed by the base station and / or other network nodes other than the base station (e.g., Obviously, this can be done by MME or S-GW, but not limited to these. Although the case where there is one network node other than the base station in the above is illustrated, a combination of a plurality of other network nodes (for example, MME and S-GW) may be used.

  Information or the like can be output from the upper layer (or lower layer) to the lower layer (or upper layer). Input / output may be performed via a plurality of network nodes.

  Input / output information and the like may be stored in a specific location (for example, a memory) or may be managed by a management table. Input / output information and the like can be overwritten, updated, or additionally written. The output information or the like may be deleted. The input information or the like may be transmitted to another device.

  Information, signals, etc. described herein may be represented using any of a variety of different technologies. For example, data, commands, commands, information, signals, bits, symbols, chips, etc. that may be referred to throughout the above description are voltages, currents, electromagnetic waves, magnetic fields or magnetic particles, light fields or photons, or any of these May be represented by a combination of

  Note that the terms described in this specification and / or terms necessary for understanding this specification may be replaced with terms having the same or similar meaning. For example, the channel and / or symbol may be a signal.

  As used herein, the terms “traffic”, “packet” and “data” may be used interchangeably.

  The user equipment UE is defined by those skilled in the art as a subscriber station, mobile unit, subscriber unit, wireless unit, remote unit, mobile device, wireless device, wireless communication device, remote device, mobile subscriber station, access terminal, mobile terminal, It may also be referred to as a wireless terminal, remote terminal, handset, user agent, mobile client, client, or some other appropriate terminology.

  Base station 10 may also be referred to by those skilled in the art as NB (Node B), base station, Base Station, access point, femto cell, small cell or some other suitable terminology. .

  As used herein, the terms “determining” and “determining” may encompass a wide variety of actions. “Judgment” and “determination” are, for example, judgment, calculation, calculation, processing, derivation, investigating, looking up (eg, table , Searching in a database or another data structure), considering ascertaining as “determining”, “deciding”, and the like. In addition, “determination” and “determination” include receiving (for example, receiving information), transmitting (for example, transmitting information), input (input), output (output), and access. (accessing) (e.g., accessing data in memory) may be considered as "determined" or "determined". In addition, “determination” and “decision” means that “resolving”, “selecting”, “choosing”, “establishing”, and “comparing” are regarded as “determining” and “deciding”. May be included. In other words, “determination” and “determination” may include considering some operation as “determination” and “determination”.

  The processing procedures (No. 1 to No. 3) described in this specification may be used singly, in combination, or may be switched according to execution. In addition, notification of predetermined information (for example, notification of being “X”) is not limited to explicitly performed, but is performed implicitly (for example, notification of the predetermined information is not performed). Also good.

  As used herein, the phrase “based on” does not mean “based only on,” unless expressly specified otherwise. In other words, the phrase “based on” means both “based only on” and “based at least on.”

  Any reference to elements using the designations "first", "second", etc. as used herein does not generally limit the amount or order of those elements. These designations can be used herein as a convenient way to distinguish between two or more elements. Thus, a reference to the first and second elements does not mean that only two elements can be employed there, or that in some way the first element must precede the second element.

  These terms are similar to the term “comprising” as long as “including”, “including”, and variations thereof, are used herein or in the claims. It is intended to be comprehensive. Furthermore, the term “or” as used herein or in the claims is not intended to be an exclusive OR.

  A radio frame may be composed of one or more frames in the time domain. Each frame or frames in the time domain may be referred to as a subframe. A subframe may further be composed of one or more slots in the time domain. A slot may further be composed of one or more symbols (OFDM symbols, SC-FDMA symbols, etc.) in the time domain. Each of the radio frame, subframe, slot, and symbol represents a time unit for transmitting a signal. Radio frames, subframes, slots, and symbols may be called differently corresponding to each. For example, in the LTE system, the base station performs scheduling for allocating radio resources (frequency bandwidth or transmission power that can be used in each mobile station) to each mobile station. The minimum scheduling time unit may be referred to as TTI. For example, one subframe may be called TTI, a plurality of consecutive subframes may be called TTI, and one slot may be called TTI. A resource block (RB) is a resource allocation unit in the time domain and the frequency domain, and may include one or a plurality of continuous subcarriers in the frequency domain. In the time domain of the resource block, one or a plurality of symbols may be included, and one slot, one subframe, or a length of 1 TTI may be included. One TTI and one subframe may each be composed of one or a plurality of resource blocks. The structure of the radio frame described above is merely an example, and the number of subframes included in the radio frame, the number of slots included in the subframe, the number of symbols and resource blocks included in the slots, and the subframes included in the resource block The number of carriers can be variously changed.

  Throughout this disclosure, if articles are added by translation, for example, a, an, and the in English, these articles must be clearly indicated otherwise in context, Including multiple things.

  Although the present invention has been described in detail above, it will be apparent to those skilled in the art that the present invention is not limited to the embodiments described herein. The present invention can be implemented as modified and changed modes without departing from the spirit and scope of the present invention defined by the description of the scope of claims. Therefore, the description of the present specification is for illustrative purposes and does not have any limiting meaning to the present invention.

  In the embodiment, the normal TTI is an example of a TTI having a predetermined length. The short TTI is an example of a TTI having a shorter time length than a predetermined length TTI.

UE user apparatus 10 base station 101 signal transmission unit 102 signal reception unit 103 acquisition unit 201 signal transmission unit 202 signal reception unit 203 scheduling unit 204 notification unit 1001 processor 1002 memory 1003 storage 1004 communication device 1005 input device 1006 output device

Claims (6)

A user apparatus in a wireless communication system that supports multiple lengths of TTI and includes a base station and a user apparatus,
An acquisition unit that acquires, from a base station, information indicating a plurality of UL resources allocated to a plurality of symbols included in a TTI having a predetermined length and capable of transmitting a scheduling request;
A transmitter that selects a UL resource from the plurality of UL resources, and transmits a scheduling request to the base station using the selected UL resource;
A user device. When the transmission unit requests allocation of a UL resource capable of transmitting data with a TTI having a time length shorter than the TTI having the predetermined length, data can be transmitted with a TTI having a time length shorter than the TTI having the predetermined length. Transmitting the scheduling request according to a scheduling request transmission method indicating requesting allocation of UL resources;
The user device according to claim 1. One scheduling request means a data size of a predetermined unit,
The transmission unit calculates the number of scheduling requests to be transmitted to the base station based on the data size of the predetermined unit and the data size of UL data stored in the transmission buffer of the user apparatus, and calculates The user apparatus according to claim 1 or 2, wherein a number of UL resources equal to the number is selected from the plurality of UL resources, and a scheduling request is transmitted using each of the selected plurality of UL resources. The acquisition unit is a UL resource divided into a plurality of regions in the time direction within the TTI of the predetermined length, and scheduling information indicating a UL resource that can transmit a transport block with each UL resource. Obtained from the base station,
4. The transmission unit according to claim 1, wherein the transmission unit transmits a buffer status report using a UL resource corresponding to any one of the UL resources divided into the plurality of regions. 5. User device. A base station in a wireless communication system that supports multiple lengths of TTI and includes a base station and a user equipment,
A notification unit for notifying the user apparatus of information indicating a plurality of UL resources allocated to a plurality of symbols within 1 TTI and capable of transmitting a scheduling request;
A receiving unit that receives a scheduling request with one or more UL resources selected from the plurality of UL resources;
Base station with A signal transmission method executed by a user apparatus in a radio communication system that supports a plurality of lengths of TTI and includes a base station and a user apparatus,
Obtaining from a base station information indicating a plurality of UL resources allocated to a plurality of symbols included in a TTI having a predetermined length and capable of transmitting a scheduling request;
Selecting a UL resource from the plurality of UL resources, and transmitting a scheduling request to the base station using the selected UL resource;
A signal transmission method comprising:

Images